错误TypeError：无法读取angular5中未定义的ContaComponent.loadComponent的属性'style'

Question

我正在尝试删除jQuery代码并实现以下代码，如下所示：-

 $('.abc').hide();
 $('.abc').show();

在angular5中为：-

(<any>document.getElementsByClassName('abc'))[0]['style'].display = 'none';
(<any>document.getElementsByClassName('abc'))[0]['style'].display = 'block';

获取错误：-

ERROR TypeError: Cannot read property 'style' of undefined     at ContaComponent.loadComponent 

However, jQuery code is working fine but I want to remove jQuery dependency as above but getting error.